Surface curvature effect on the calculation of separation bubble

AIAA Journal ◽  
1989 ◽  
Vol 27 (9) ◽  
pp. 1288-1290 ◽  
Author(s):  
D. H. Choi ◽  
D. J. Kang
Keyword(s):  
Separation Bubble ◽  
Surface Curvature ◽  
Curvature Effect

The Surface Curvature Effect of Single-Walled Carbon Nanotube on Its Cation-π Interaction with Monovalent Cations

2012 ◽  
Vol 9 (12) ◽  
pp. 2107-2112
Author(s):  
Arthit Vongachariya ◽  
Chularat Iamsamai ◽  
Oraphan Saengsawang ◽  
Thanyada Rungrotmongkol ◽  
Stephan T. Dubas ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Surface Curvature ◽  
Curvature Effect ◽  
Monovalent Cations ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon

Surface Curvature Effect on Slot-Air-Jet Impingement Cooling Flow and Heat Transfer Process

1991 ◽  
Vol 113 (4) ◽  
pp. 858-864 ◽  
Author(s):  
C. Gau ◽  
C. M. Chung
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Transfer Process ◽  
Convex Surface ◽  
Heat Transfer Process ◽  
Surface Curvature ◽  
Curvature Effect ◽  
Impingement Cooling ◽  
Cooling Flow ◽  
Air Jet

Experiments are performed to study surface curvature effects on the impingement cooling flow and the heat transfer processes over a concave and a convex surface. A single air jet issuing from different size slots continuously impinges normally on the concave side or the convexside of a heated semicylindrical surface. An electrical resistance wire is used to generate smoke, which allows us to visualize the impinging flow structure. The local heat transfer Nusselt number along the surfaces is measured. For impingement on a convex surface, three-dimensional counterrotating vortices on the stagnation point are initiated, which result in the enhancement of the heat transfer process. For impingement on a concave surface, the heat transfer Nusselt number increases with increasing surface curvature, which suggests the initiation of Taylor–Go¨rtler vortices along the surface. In the experiment, the Reynolds number ranges from 6000 to 350,000, the slot-to-plate spacing from 2 to 16, and the diameter-to-slot-width ratio D/b from 8 to 45.7. Correlations of both the stagnation point and the average Nusselt number over the curved surface, which account for the surface curvature effect, are presented.

Numerical investigation of surface curvature effect on the self-propelled capability of coalesced drops

2020 ◽  
Vol 32 (12) ◽  
pp. 122117
Author(s):  
Yan Chen ◽  
Ahmed Islam ◽  
Mark Sussman ◽  
Yongsheng Lian
Keyword(s):  
Numerical Investigation ◽  
Surface Curvature ◽  
The Self ◽  
Curvature Effect

Numerical Investigation of Surface Curvature Effects on Aerofoil Aerodynamic Performance

2015 ◽  
Vol 798 ◽  
pp. 589-595 ◽  
Author(s):  
Xiang Shen ◽  
Theodosios Korakianitis ◽  
Eldad Avital
Keyword(s):  
Separation Bubble ◽  
Circle Method ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Aerodynamic Performance ◽  
Surface Curvature ◽  
Operating Conditions ◽  
Curvature Effects ◽  
Curvature Continuity ◽  
Curvature Distribution

The prescribed surface curvature distribution blade design (CIRCLE) method optimises aerofoils and blades by controlling curvature continuity and slope of curvature distribution along their surfaces. The symmetrical NACA0012 exhibits a surface curvature discontinuity at the leading edge point, and the non-symmetrical E387 exhibits slope-of-curvature discontinuities in the surface. The CIRCLE method is applied to both aerofoils to remove both surface curvature and slope-of-curvature discontinuities. Computational fluid dynamics analyses are used to investigate the curvature effects on aerodynamic performance of the original and modified aerofoils. These results are compared with experimental data obtained from tests on the original aerofoil geometry. The computed aerodynamic advantages of the modified aerofoil are analysed in different operating conditions. The leading edge singularity of NACA0012 is removed and it is shown that the surface curvature discontinuity affects the aerodynamic performance near the stalling angle of attack. The discontinuous slope-of-curvature distribution of E387 influences the size of the laminar separation bubble at lower Reynolds numbers, and it affects the inherent profile of the aerofoil at higher Reynolds numbers. It is concluded that the surface curvature distribution of aerofoils has a significant effect on aerofoil aerodynamic performance, which can be improved by redesigning the surface curvature distribution of the original aerofoil geometry.

Longitudinal surface curvature effect in magnetohydrodynamics

1975 ◽  
Vol 9 (4) ◽  
pp. 301-310
Author(s):  
N. G. Bodas ◽  
B. K. Gupta
Keyword(s):  
Surface Curvature ◽  
Curvature Effect

Effects of Curvature Continuity of Compressor Blade Profiles on Their Performances

2014 ◽  
Author(s):  
Yin Song ◽  
Chunwei Gu
Keyword(s):  
Separation Bubble ◽  
Leading Edge ◽  
Optimization Method ◽  
Surface Curvature ◽  
Compressor Blade ◽  
Navier Stokes ◽  
Boundary Layer Equations ◽  
Pressure Spike ◽  
Curvature Continuity ◽  
Continuous Curvature

Curvature discontinuity may exist in the surface, especially at the leading edge, of a compressor blade. The importance of curvature continuity or discontinuity has been realized, but its definite influences and mechanisms still need research. In this paper, an optimization method is proposed to design continuous-curvature blade profiles from datum blades, and a Reynolds-Averaged Navier-Stokes (RANS) solver with a transition model is used to examine the flowfields and performances of different blade profiles. Large eddy simulations of several cases are also presented to validate the RANS results. The effects of leading-edge-blend-point curvature continuity and the main-surface curvature continuity are studied separately. The results show that the curvature continuity at the leading-edge blend point helps to eliminate the separation bubble, and thus improves the blade performance. The main-surface curvature continuity is also found beneficial, although its effects are much smaller than those of the blend-point curvature continuity. Boundary-layer equations of the blade profiles are analyzed in terms of order of magnitude to further study the different curvature-continuity effects of the blend point and main surface theoretically. The analysis reveals the physical facts that produce the pressure spike around a leading-edge blend point with a discontinuous curvature, and thus explains how the optimized continuous-curvature leading edge removes the pressure spike and the related separation. The analysis also finds that the high spike appearing near the nose of a continuous-curvature leading edge at larger incidences is controlled by the large nose curvature rather than curvature discontinuity. The dual separation mechanisms also help to solve the so-called sharp leading edge paradox.

The Surface Curvature Effect on Performance of a Laboratory Scale Tidal Turbine

2019 ◽  
pp. 101-113
Author(s):  
Kaiming Ai ◽  
Eldad Avital ◽  
Xiang Shen ◽  
Abdus Samad ◽  
Nithya Venkatesan
Keyword(s):  
Surface Curvature ◽  
Laboratory Scale ◽  
Curvature Effect ◽  
Tidal Turbine
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